The nose has the important function of first contact with inspired air. This air is laden with pollutants, suspended material, microbes, and noxious substances. Air can be cold and dry and often needs warming and humidification before entering the lower respiratory tract. The nose also serves as a sensitive detector of air-borne chemicals and helps sense the flavor of food and drink. The nose further serves an important role in the immune system because it is the first site of contact of many air-borne allergens with the body's defense system.
Many people have difficulty breathing through their nose. Some causes for restricted breathing are congestion of the nasal lining from allergies, deviation of the nasal septum, i.e., the partition between the two nostrils, which narrows one or both nasal chambers, or by a droopy nasal tip.
During exercise, nasal breathing becomes more difficult and some people are forced to open their mouths to get enough air. When exercising, it is necessary to breath rapidly. Upon rapid breathing, a negative pressure is created in the nasal chamber forcing the lower sides of the nose to collapse which obstructs breathing. If nasal breathing becomes obstructed, it is necessary to breath through the mouth in order to obtain an adequate amount of air. When a person becomes a mouth breather, the important functions of the nose are bypassed.
The nose accounts for approximately half of the total airway resistance to airflow. Nasal obstruction can contribute to an increase in snoring and sleep apnea frequency and severity. Snoring sounds have been associated with increased upper airway occlusion. Upper airway narrowing, collapsability and resistance are recognized factors contributing to snoring and obstructive sleep apnea. Certain loud snorers have an increased internal resistive load that results in repetitive arousals from sleep.
The nose is often affected by allergies, the flu or a cold. The common cold, although not usually a serious illness, is a highly prevalent, discomforting and annoying affliction. The term is applied to minor respiratory illnesses caused by a variety of different respiratory viruses. While rhinoviruses are the major known cause of common colds, accounting for approximately 30 percent of colds in adults, viruses in several other groups are also important. While immune responses occur, and infection with some respiratory tract viruses therefore could be prevented by a vaccine, developments of a polytypic vaccine to cover all possible agents is impractical. Thus, the problem of controlling acute upper respiratory disease presents complex challenges, and the long-desired discovery of a single cure for the common cold is an unrealistic expectation.
Early symptoms may be minimal with only mild malaise, sore throat and nasal complaints. With rhinovirus infection, symptoms of nasal discharge, nasal congestion, and sneezing usually commence on the first day of illness and progress to maximum severity by the second or third day. Along with nasal symptoms may come sore, dry or scratchy throat and hoarseness and cough. Other symptoms may include mild burning of the eyes, loss of smell and taste, a feeling of pressure or fullness in the sinuses or ears, headache, and vocal impairment. Fever can occur, but is uncommon. Influenza infection generally includes fever, often of sudden onset and persisting for several days, and with great severity; generalized aches and pains; fatigue and weakness; and chest discomfort.
The costs of treating colds with over-the-counter medications in the United States is estimated at an annual cost of over 1.5 billion dollars. The direct costs of treatment in outpatient clinics is estimated at almost four billion dollars. Indirect costs, based on amount of lost wages because of restricted activity are substantially higher.
Nasal dilators have been suggested for aiding breathing through the nose during snoring, athletic events, and for treating the symptoms of the common cold or flu. There have been traditionally two types of dilators which have been effective in humans. One type uses small rings or cages connected to a resilient structure. The rings are inserted into each nasal passage while the resilient structure spreads to provide unobstructed breathing. These dilators have been criticized because they are often uncomfortable to wear. Since the cages or rings are inserted into contact with sensitive nasal tissue, they have been known to cause irritation and itching. Such devices are disclosed in U.S. Pat. No. 3,710,799 to Caballero and the NOZOVENT dilator disclosed in Petruson D310,565.
More recently, advancements have been made in nasal dilators which attach to the outer wall tissue of the nose and aid in preventing the inner nasal tissue from drawing in during breathing. Such dilators include a flexible strip of material adhesively attached to a substrate. The dilator is fastened to the nose and the resilient material acts to keep the left and right nasal passages from drawing in or collapsing during inhalation. This usually occurs due to a malformation, such as a deviated septum or due to swelling during allergic reactions and the like. Examples of nasal dilators which are adhesively attached to the outer skin of a human nose are disclosed in Doubek et al., U.S. Pat. No. 5,533,503 and Muchin, U.S. Pat. No. 5,546,929.
In related application U.S. Pat. No. 5,706,800, which is hereby incorporated by reference, there is disclosed a medicated nasal dilator including essential fragrance oils, such as camphor and menthol. Such fragrance oils are commonly used in the treatment of nasal congestion, bronchial asthma and cough suppression. They are widely available in the form of hard confection drops, nasal sprays and inhalers. The '800 patent discloses a medicated nasal dilator having a resilient layer or portion which helps to provide mechanical dilation while the incorporated fragrance introduces an aromatic substance, preferably a medication, for treating the patient's symptoms.
Early attempts to produce medicated dilators have uncovered several shortcomings that need to be addressed. Aromatic substances, such as menthol and camphor, while therapeutically effective, are highly volatile. Oil-base carriers, such as petrolatum, commonly called petroleum jelly, while effective in containing volatile menthol and camphor in airtight containers, quickly release these oily substances into the atmosphere when exposed to air. Accordingly, nasal dilators impregnated with fragrance oils generally lose their odor quickly because the scent dissipates during the shelf life of the product.
Although hermetic foil packaging has been discussed, scented dilators remain relatively stable only until the packaging is opened. Without individually wrapping each dilator, the remaining scented dilators dissipate their oils quickly. Separately packaging each dilator in its own hermetic packaging, may improve shelf life, but it increases the expense of the product and makes it generally more inconvenient to use due to the tenacious materials, such as mylar, etc., used to make hermetic packaging. Additionally, such packaging fails to improve upon the in-use duration of the fragrance when exposed to perspiration, body heat, dirt and dust, and the time demands of a full night's sleep.
Another drawback associated with scented dilators is the tendency of the nasal nerve endings to become desensitized to the fragrance, long before the fragrance has dissipated from the product. Due to the extended periods of time for which nasal dilators and strips are recommended, from an hour to 12 hours, prolonged exposure to the same volatile oil or mixture, such as menthol or camphor, generally engenders a phenomena of adaptation called “olfactory saturation”, which results in a gradual loss of smell of the active fragrance to the wearer. This, of course, is a distraction to wearers, who may feel the need to replace the dilator with a fresh product, only to find that a new dilator fails to completely refresh the olfactory impression.
Fragrance oils are also known to break down the structure of known pressure-sensitive adhesives used to attach nasal dilators to skin, such as polyacrylate or polyvinylethyl ether blend adhesives. Such fragrances tend to migrate to the adhesive layer, even when they are incorporated into the fabric substrate. When fragrance oil mixes with the adhesive, it plasticizes the adhesive, making it less cohesive and more sticky. The internal strength of the adhesive is reduced considerably. This can have the unfortunate, unintended effect of causing a nasal dilator, which is already exerting release pressure due to resilient members contained therein, to completely remove its adhesive attachment from the nose. To make matters worse, when it is desired to remove the dilator or strip, portions of the plasticized adhesive remain on the skin surface, leaving it tacky and unsightly.
There also remains a concern relating to the proper dosage of fragrance oils used for nasal dilators and strips. If the fragrance oil concentration is too high, it can irritate the eyes causing tears. If the dosage is too low, there is insufficient fragrance to produce an olfactory effective amount, which, in the case of cosmetic fragrances, makes the product less appealing to the consumer, and in the case of medicated aromatics, renders these devices therapeutically ineffective.
Accordingly, there remains a need for improved delivery systems which may incorporate fragrances, transdermal medications and other ingredients. Such products remain an emerging technology, requiring innovation to overcome the problems associated with short fragrance shelf life and in-use effectiveness, olfactory saturation, and dosage issues.